TWI586468B - Method and apparatus of laser processing - Google Patents

Description

Laser processing method and device

The present invention relates to a laser processing method and apparatus for processing a workpiece by irradiating a laser beam.

In the laser processing apparatus, there is a case where the output of the laser oscillator is gradually lowered due to deterioration or individual difference of the laser oscillator. If the output of the laser oscillator is lowered, it may be impossible to perform necessary processing on the workpiece. Specifically, it may be impossible to open a hole of a desired diameter to a workpiece.

In the related art, Patent Document 1 below discloses a technique in which a movable lens is provided between an aperture and a laser oscillator, and the position of the movable lens is changed to cause laser irradiation on the opening. The beam diameter is varied to adjust the laser power after passing through the opening, thereby improving the reproducibility of the process.

Further, Patent Document 2 below discloses a technique in which the concentrating lens is moved in accordance with the height of the work to focus the focus of the laser beam on the surface of the workpiece, thereby obtaining a desired processing width.

(previous technical literature) (Patent Literature)

Patent Document 1: Japanese Patent Laid-Open Publication No. 2000-176661

Patent Document 2: Japanese Patent Laid-Open Publication No. 2009-208093

However, in the technique described in Patent Document 1, when the diameter of the laser beam on the opening is reduced, the difference in the intensity profile of the laser beam after passing through the opening is changed between the optical axis portion and the edge portion. Big. Further, the strength of the edge portion of the laser beam reaching the workpiece is insufficient, and the hole of a desired diameter may not be opened.

Further, the technique described in Patent Document 2 does not include an opening, and does not disclose the energy of the laser beam adjusted by the opening. That is, it does not consider that the energy of the laser beam emitted from the laser oscillator may gradually decrease due to the deterioration of the time or the individual difference of the laser oscillator. Further, the technique described in the above Patent Document 2 is a technique of moving the condenser lens in accordance with the height of the workpiece to focus the focus of the laser beam on the surface of the workpiece.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a laser processing method and apparatus capable of performing desired laser processing on a workpiece even if the output of the laser oscillator is lowered.

In order to solve the above problems and achieve the object, the laser processing method of the present invention includes the following steps: a first step of irradiating a laser beam emitted from a laser oscillator to an incident optical system of a mask. The opposite of the direction of travel of the laser beam or the direction of travel of the laser beam Moving to adjust the energy of the laser beam that has passed through the opening of the mask; and in the second step, irradiating the laser beam that has passed through the opening to the workpiece according to the movement of the incident optical system The transfer optical system moves toward the direction of travel of the laser beam or the direction of travel of the laser beam to adjust the diameter of the laser beam on the surface to be processed of the workpiece; the second step is to make the workpiece The beam diameter of the portion on the surface to be processed that is higher than the processing threshold is increased.

The laser processing method and apparatus of the present invention achieve the effect of performing desired laser processing on a workpiece even if the output of the laser oscillator is lowered.

1, 1A, 1B, 81‧‧ ‧ laser processing equipment

2, 2A, 82‧‧ ‧ laser oscillator

3, 83‧‧‧Infrared optical system

4‧‧‧1st drive department

5, 85‧‧‧ mask

5a, 85a‧‧‧ openings

6, 86‧‧‧Transmission optical system

7, 87‧‧‧Transfer optical system

8‧‧‧2nd drive department

9‧‧‧ stage

10‧‧‧3rd drive department

11‧‧‧ Sensor

12‧‧‧Memory Department

12a to 12c‧‧

13, 88‧‧‧Control Department

14, 89‧‧‧Processed objects

15a to 15d, 90a to 90d‧‧‧ laser beam

16, 18, 100‧ ‧ the direction of travel of the laser beam

17, 19, 101‧‧ ‧ the opposite direction of the direction of travel of the laser beam

20, 91‧‧‧ Spotlights

30, 31, 35, 92, 94 to 96 ‧ ‧ intensity distribution of laser beams

32‧‧‧The portion of the laser beam containing the optical axis

33, 34, 97, 98‧‧ ‧ the peripheral part of the laser beam

36, 93‧‧‧ diameter

37, 99‧‧‧ Processing threshold

40 to 44, 60 to 63‧‧ lines

45 to 49, 64 to 67 ‧ ‧ intersections

84‧‧‧ Drive Department

S100, S102, S104, S106, S108, S110, S112, S120, S122‧‧ steps

Fig. 1 is a view showing the configuration of a laser processing apparatus according to a first embodiment.

Fig. 2 is a view showing the intensity distribution of the laser beam passing through the opening in the first embodiment.

Fig. 3 is a view showing the intensity distribution of the laser beam on the surface to be processed of the workpiece in the first embodiment.

Fig. 4 is a view showing the intensity distribution of the laser beam on the surface to be processed of the workpiece in the first embodiment.

Fig. 5 is a flow chart showing a laser processing method according to the first embodiment.

Fig. 6 is a graph showing the relationship between the position of the incident optical system, the position of the transfer optical system, and the processing aperture in the first embodiment.

Fig. 7 is a view showing a table stored in the memory unit in the first embodiment.

Fig. 8 is a flow chart showing the laser processing method of the first embodiment.

Fig. 9 is a view showing a state in which the energy of the laser beam of the laser processing apparatus is adjusted in the first embodiment.

Fig. 10 is a view showing the configuration of a laser processing apparatus according to a second embodiment.

Fig. 11 is a view showing the configuration of a laser processing apparatus according to a third embodiment.

Fig. 12 is a graph showing the relationship between the position of the incident optical system, the position of the transfer optical system, and the processing aperture in the third embodiment.

Fig. 13 is a view showing a table memorized by the memory unit in the third embodiment.

Fig. 14 is a view showing the configuration of a laser processing apparatus of a comparative example.

Fig. 15 is a view showing the intensity distribution of the laser beam on the mask in the comparative example.

Fig. 16 is a view showing the intensity distribution of the laser beam after passing through the opening portion in the comparative example.

Fig. 17 is a view showing the intensity distribution of the laser beam on the mask in the comparative example.

Fig. 18 is a view showing the intensity distribution of the laser beam passing through the opening portion in the comparative example.

Hereinafter, a laser processing method and apparatus according to an embodiment of the present invention will be described in detail based on the drawings. In addition, the present invention is not subject to the following The embodiment is limited.

Embodiment 1.

Fig. 1 is a view showing the configuration of a laser processing apparatus according to a first embodiment. As shown in Fig. 1, the laser processing apparatus 1 includes a laser oscillator 2 that emits a laser beam 15a, an incident optical system 3 that emits a laser beam 15a, and a first driving unit 4. The incident optical system 3 is moved in the direction of travel 16 of the laser beam 15a or in the opposite direction 17 of the direction of travel 16 of the laser beam 15a.

Further, the laser processing apparatus 1 further includes a mask 5 having an aperture 5a through which a part of the laser beam 15b passing through the incident optical system 3 passes; the transmission optical system 6 is transmitted through the opening 5a. The subsequent laser beam 15c; the transfer optical system 7 is incident on the laser beam 15c transmitted by the transmission optical system 6, and the image of the opening portion 5a is transferred to the surface to be processed of the workpiece 14; The second drive unit 8 moves the transfer optical system 7 in the traveling direction 18 of the laser beam 15c or the direction 19 of the traveling direction 18 of the laser beam 15c.

Further, the laser processing apparatus 1 further includes a table 9 for placing the workpiece 14 and a third driving unit 10 for causing the stage 9 to cross the traveling direction 18 of the laser beam 15c. Moving; a sensor 11 is disposed on the stage 9, measuring the laser beam 15c; the memory unit 12 is a memory table 12a; and the control unit 13 is for controlling the laser oscillator 2 and the first driving unit 4. The second drive unit 8 and the third drive unit 10.

In Fig. 1, the incident optical system 3 is a lens. But it can also be a plurality of lenses. The incident optical system 3 is movable toward the traveling direction 16 of the laser beam 15a or the direction 17 of the traveling direction 16 of the laser beam 15a. The control unit 13 can adjust the beam diameter of the laser beam 15b incident on the mask 5 by moving the incident optical system 3. Thereby, the control unit 13 can change the ratio of the laser beam 15c to the entire laser beam 15b, and can adjust the energy of the laser beam 15c.

The incident optical system 3 is initially positioned at a position where the energy of the laser beam 15c becomes suitable for the processing of the workpiece 14. In addition, the position of the incident optical system 3 at this time is called the reference position of the incident optical system 3 below.

The transport optical system 6 is constructed in one or a plurality of mirrors. The transport optical system 6 can also include a scan mirror. The scanning mirror is, for example, a galvano mirror. The transfer optical system 7 can also be an f θ lens.

The transfer optical system 7 is positioned at a position where the image of the opening 5a is projected onto the surface to be processed of the workpiece 14 at the initial stage. In addition, the position of the transfer optical system 7 at this time is called the reference position of the transcription optical system 7 below.

Next, an outline of the operation of the laser processing apparatus 1 will be described. The laser beam 15a emitted from the laser oscillator 2 is first incident on the incident optical system 3. The laser beam 15b after changing the beam diameter of the laser beam 15a by the incident optical system 3 is incident on the mask 5. In Fig. 1, the laser beam 15b is condensed at the condensing point 20 and then diverge into the mask 5, but it can also enter the mask 5 while maintaining the condensing state. straight (collimate) light and then enter the mask 5.

The control unit 13 controls the position of the incident optical system 3 such that the beam diameter of the laser beam 15b on the mask 5 is larger than the opening diameter of the opening 5a. Thereby, a part of the laser beam 15b passes through the opening 5a, and becomes the laser beam 15c. At this time, even if the energy of the laser beam 15a is lowered by the individual difference of the laser oscillator 2 or the deterioration over time, the control unit 13 is configured to make the energy of the laser beam 15c passing through the opening 5a constant. The position of the incident optical system 3 is adjusted.

Specifically, if the energy of the laser beam 15a emitted from the laser oscillator 2 is lowered, the control unit 13 moves the incident optical system 3 toward the traveling direction 16 of the laser beam 15a to narrow the laser beam 15b in the mask. The beam diameter on 5. Thereby, the control unit 13 can increase the ratio of the laser beam 15c to the entire laser beam 15b, and can maintain the energy of the laser beam 15c.

The laser beam 15c that has passed through the opening 5a is incident on the transfer optical system 7 by the transmission optical system 6. The transfer optical system 7 transfers the image of the opening 5a to the surface to be processed of the workpiece 14. Thereby, a machined hole corresponding to the opening diameter of the opening portion 5a is formed in the workpiece 14. In addition, the processing hole may be a bottomed hole or a through hole.

Here, a comparative example will be described. Fig. 14 is a view showing the configuration of a laser processing apparatus of a comparative example. As shown in Fig. 14, the laser processing apparatus 81 includes a laser oscillator 82 that emits a laser beam 90a, an incident optical system 83 that emits a laser beam 90a, and a drive unit 84 that causes incident optics. System 83 is directed toward the direction of travel of laser beam 90a or by lightning The opposite direction 101 of the traveling direction 100 of the beam 90a moves.

Further, the laser processing apparatus 81 further includes a mask 85 having an opening 85a through which a part of the laser beam 90b passing through the incident optical system 83 passes, and a transmission optical system 86 that transmits the lightning after passing through the opening 85a. The light beam 90c; the transfer optical system 87 is incident on the laser beam 90c transmitted from the transmission optical system 86, and the image of the opening 85a is transferred to the surface to be processed of the workpiece 89; the control portion 88, The laser oscillator 82 and the drive unit 84 are controlled.

The laser beam 90a emitted from the laser oscillator 82 is first incident on the incident optical system 83. The laser beam 90b after changing the beam diameter of the laser beam 90a by the incident optical system 83 is incident on the mask 85. In Fig. 14, the laser beam 90b is first condensed at the condensing point 91, and then diverged to enter the mask 85.

The laser beam 90c that has passed through the opening 85a is incident on the transfer optical system 87 by the transmission optical system 86. The transfer optical system 87 transfers the image of the opening 85a to the surface to be processed of the workpiece 89. Thereby, a machined hole corresponding to the opening diameter of the opening 85a is formed in the workpiece 89.

Fig. 15 is a view showing the intensity distribution of the laser beam on the mask in the comparative example. Fig. 16 is a view showing the intensity distribution of the laser beam after passing through the opening portion in the comparative example. In addition, the intensity distribution of the laser beam is also referred to as a beam shape or a mode shape.

As shown in Fig. 15, the intensity distribution 92 of the laser beam 90b on the mask 85 is a gauss shape. In addition, the laser beam 90b A part of it passes through the opening 85a having a diameter 93. As shown in Fig. 16, the intensity distribution 94 of the laser beam 90c passing through the opening 85a has a diameter 93. At this time, the beam intensity of the entire laser beam 90c is higher than the processing threshold 99, and a machined hole having a desired diameter can be formed in the workpiece 89.

Next, a description will be given of a case where the energy of the laser beam 90a is lowered due to the individual difference of the laser oscillator 82 or deterioration over time.

At this time, referring again to Fig. 14, the control unit 88 moves the incident optical system 83 toward the traveling direction 100 of the laser beam 90a to reduce the beam diameter of the laser beam 90b on the mask 85. Thereby, the control unit 88 can increase the ratio of the laser beam 90c to the entire laser beam 90b, and can maintain the energy of the laser beam 90c.

Fig. 17 is a view showing the intensity distribution of the laser beam on the mask in the comparative example. Fig. 18 is a view showing the intensity distribution of the laser beam passing through the opening portion in the comparative example.

As shown in Fig. 17, the intensity distribution 95 of the laser beam 90b on the mask 85 is Gaussian. Here, since the diameter of the laser beam 90b becomes smaller than the intensity distribution 92 before the output of the laser oscillator 82 shown in Fig. 15, the intensity distribution 95 of the laser beam 90b on the mask 85 becomes Sharp shape. Further, the portion passing through the opening portion 85a includes a portion having a low beam intensity to the peripheral portion of the laser beam 90b.

Further, a part of the laser beam 90b passes through the opening portion 85a having a diameter 93. As shown in Fig. 18, the intensity distribution 96 of the laser beam 90c passing through the opening 85a has a diameter 93. At this time, the laser The beam intensity of the portion of the beam 90c containing the optical axis is above the processing threshold 99. However, the beam intensity of the peripheral portions 97 and 98 of the laser beam 90c is lower than the processing threshold 99. Therefore, the laser processing apparatus 81 cannot form a machined hole of a desired diameter in the workpiece 89. Specifically, the laser processing apparatus 81 can only form a machined hole having a diameter smaller than a desired diameter in the workpiece 89.

Next, the principle of the laser processing method according to the first embodiment will be described. The optical system of the laser processing apparatus 1 shown in Fig. 1 is configured to transfer the image of the opening 5a to the workpiece 14, so that the diameter of the processing hole depends on the opening diameter of the opening 5a.

However, when the output of the laser oscillator 82 is lowered and the control unit 13 controls the beam diameter of the laser beam 15b incident on the mask 5, the intensity distribution of the laser beam 15c after passing through the opening 5a is obtained. The system becomes a sharp shape.

Fig. 2 is a view showing the intensity distribution of the laser beam passing through the opening in the first embodiment. The intensity distribution 30 of the laser beam 15c passing through the opening 5a shown in Fig. 2 includes a portion having a low beam intensity to the peripheral portion.

Fig. 3 is a view showing the intensity distribution of the laser beam on the surface to be processed of the workpiece in the first embodiment. In the intensity distribution 31 of the laser beam 15d on the surface to be processed of the workpiece 14 shown in Fig. 3, the beam intensity of the portion 32 containing the optical axis of the laser beam 15d on the surface of the workpiece 14 is higher than that. Processing threshold 37. However, the beam intensity of the peripheral portions 33 and 34 of the laser beam 15d is lower than the processing threshold 37. Therefore, Ray The shot processing apparatus 1 cannot form a machined hole of a desired diameter in the workpiece 14. Specifically, the laser processing apparatus 1 can only form a machined hole having a diameter smaller than a desired diameter in the workpiece 14.

On the other hand, the control unit 13 causes the transfer optical system 7 to move in the traveling direction 18 of the laser beam 15d from the reference position at which the image of the opening 5a is projected onto the workpiece 14. That is, the control unit 13 shifts the image of the opening 5a from the surface to be processed of the workpiece 14 toward the traveling direction 18 of the laser beam 15d. Thereby, the control unit 13 blurs the image of the opening 5a on the surface to be processed of the workpiece 14. In addition, the image of the opening 5a on the surface to be processed of the workpiece 14 is blurred, and the outline of the image of the opening 5a on the surface to be processed of the workpiece 14 and the boundary between the shades and the shades are commanded. Obscure and obscure. Thereby, the control unit 13 expands the beam diameter of the portion of the laser beam 15d on the surface to be processed of the workpiece 14 that is higher than the processing threshold. Thereby, the laser processing apparatus 1 increases the diameter of the machined hole to a desired machined hole diameter, thereby enabling the formation of a machined hole of a desired diameter.

Fig. 4 is a view showing the intensity distribution of the laser beam on the surface to be processed of the workpiece in the first embodiment. The control unit 13 causes the transfer optical system 7 to shift from the reference position at which the image of the opening 5a is projected onto the workpiece 14 toward the traveling direction 18 of the laser beam 15d. That is, the control unit 13 shifts the image of the opening 5a from the surface to be processed of the workpiece 14 toward the traveling direction 18 of the laser beam 15d. Thereby, the control unit 13 blurs the image of the opening 5a on the surface to be processed of the workpiece 14. Thereby, the control unit 13 will process the processed table in the workpiece 14. The beam diameter of the portion of the laser beam 15d on the surface higher than the processing threshold is enlarged.

In the intensity distribution 35 of the laser beam 15d on the surface to be processed of the workpiece 14 shown in Fig. 4, since the beam diameter of the portion of the laser beam 15d higher than the processing threshold is expanded, it is possible to form a necessary A machined hole having a diameter of 36. Further, the reason why the intensity distribution 35 becomes a wave shape is the influence of the diffraction caused by the transfer of the transcription optical system 7 from the projection position.

Next, a procedure of the laser processing method according to the first embodiment will be described. Fig. 5 is a flow chart showing the laser processing method of the first embodiment. The flowchart shown in Fig. 5 is a flowchart showing a method of obtaining the position of the incident optical system 3, the position of the transfer optical system 7, and the processing aperture. The flowchart shown in Fig. 5 can be executed when the laser processing apparatus 1 is set, or when the laser oscillator 2 is replaced. Further, a program for executing the flowchart shown in FIG. 5 can be memorized in advance in the storage unit 12.

First, in step S100, the control unit 13 drives the laser oscillator 2 to process the test object. Next, in step S102, the control unit 13 acquires the relationship between the position of the transfer optical system 7 and the processing aperture.

Next, in step S104, the control unit 13 determines whether or not the transfer optical system 7 has reached the measurement end. When it is determined in step S104 that the transfer optical system 7 has not reached the end of the metering (NO), the control unit 13 causes the transfer optical system 7 to move by a reference amount in step S106, and causes the processing to jump. Go to step S100. In addition, a reference amount is, for example, an order of micrometers.

On the other hand, when it is determined in step S104 that the transfer optical system 7 has reached the measurement end (Yes), the control unit 13 determines in step S108 whether or not the incident optical system 3 has reached the measurement end. When it is determined in step S108 that the incident optical system 3 has not reached the measurement end (No), the control unit 13 causes the incident optical system 3 to move by one reference amount in step S110. In addition, a reference amount is, for example, of the order of millimeters.

Next, in step S112, the control unit 13 returns the transfer optical system 7 to the reference position, and the process proceeds to step S100.

On the other hand, when it is determined in step S108 that the incident optical system 3 has reached the measurement end (Yes), the control unit 13 ends the processing.

Further, it is preferable to obtain the relationship between the position of the incident optical system 3, the position of the transfer optical system 7, and the processing aperture by operating the laser processing apparatus 1 in accordance with the flowchart shown in Fig. 5. However, the relationship between the position of the incident optical system 3, the position of the transfer optical system 7, and the processing aperture can be obtained by performing the flowchart shown in Fig. 5 by simulation.

Fig. 6 is a graph showing the relationship between the position of the incident optical system, the position of the transfer optical system, and the processing aperture in the first embodiment. The graph shown in Fig. 6 is obtained by simulating the flow chart shown in Fig. 5.

In the graph shown in Fig. 6, the horizontal axis represents the position of the transfer optical system 7, and the vertical axis represents the diameter of the portion of the laser beam 15d on the surface to be processed of the workpiece 14 which is higher than the processing threshold. . In addition, "-" represents that the transfer optical system 7 is moved toward the traveling direction 18 side of the laser beam 15d, and "+" represents that the transfer optical system 7 is moved toward the reverse direction 19 side of the traveling direction 18 of the laser beam 15d. .

In Fig. 6, the position of the incident optical system 3 is shown as a reference position, the position of the incident optical system 3 is a position of -1 mm from the reference position, and the position of the incident optical system 3 is a position of -2 mm from the reference position. In the case where the position of the incident optical system 3 is a position of -3 mm from the reference position and the position of the incident optical system 3 is a position of -4 mm from the reference position. Here, the "-" represents that the incident optical system 3 is moved toward the traveling direction 16 side of the laser beam 15b.

The line 40 is an approximate straight line of a sample point when the position of the incident optical system 3 is the reference position. The line 41 is an approximate straight line of the sampling point when the position of the incident optical system 3 is -1 mm from the reference position. The line 42 is an approximate straight line of the sampling point when the position of the incident optical system 3 is -2 mm from the reference position. The line 43 is an approximate straight line of the sampling point when the position of the incident optical system 3 is -3 mm from the reference position. The line 44 is an approximate straight line of the sampling point when the position of the incident optical system 3 is -4 mm from the reference position.

Here, the desired processing pore size is set to 50 μm. At this time, the intersection of the line 40, the line 41, the line 42, the line 43, and the line 44 with the diameter of the portion of the laser beam 15d on the surface to be processed of the workpiece 14 which is higher than the processing threshold is determined to be 50 μm. 45. Intersection 46, intersection 47, intersection 48 and intersection 49. The values of the horizontal axis of the intersection 45, the intersection 46, the intersection 47, the intersection 48, and the intersection 49 are such that the position of the incident optical system 3 is the reference position when the position of the incident optical system 3 is the reference position of the transfer optical system 7. When the position of -1 mm is set, the position of the incident optical system 3 is a position of -2 mm from the reference position, the position of the incident optical system 3 is a position of -3 mm from the reference position, and the position of the incident optical system 3 is a distance from the reference position - The position that should be configured when the position is 4mm.

Specifically, when the position of the incident optical system 3 is the reference position, the position of the transfer optical system 7 becomes -140 μm from the reference position. Further, when the position of the incident optical system 3 is a position of -1 mm from the reference position, the position of the transfer optical system 7 becomes -120 μm from the reference position. Further, when the position of the incident optical system 3 is a position of -2 mm from the reference position, the position of the transfer optical system 7 becomes -95 μm from the reference position. Further, when the position of the incident optical system 3 is a position of -3 mm from the reference position, the position of the transfer optical system 7 becomes -70 μm from the reference position. Further, when the position of the incident optical system 3 is a position of -4 mm from the reference position, the position of the transfer optical system 7 becomes -25 μm from the reference position.

Fig. 7 is a view showing a table stored in the memory unit of the first embodiment. Table 12a shown in Fig. 7 is a diagram illustrating the transfer of the position of the incident optical system 3 and the laser beam 15d when the diameter of the surface to be processed of the workpiece 14 becomes a desired diameter, according to the graph of Fig. 6. The relationship of the position of the optical system 7.

Fig. 8 is a flow chart showing the laser processing method of the first embodiment. The flowchart shown in Fig. 8 is a flowchart showing a method of adjusting the laser processing apparatus 1 during laser processing. The processing of the flow chart shown in Figure 8 can be performed each time laser processing is performed, or before daily operation. Execution may also be performed in consideration of the drop in the output of the laser oscillator 2. Further, the program for executing the processing of the flowchart shown in Fig. 8 can be stored in the memory unit 12.

First, in step S120, the control unit 13 moves the incident optical system 3 toward the traveling direction 16 of the laser beam 15a or the reverse direction 17 of the traveling direction 16 of the laser beam 15a to adjust the laser beam passing through the opening portion 5a. The energy of the beam 15c.

Fig. 9 is a view showing a state in which the energy of the laser beam of the laser processing apparatus is adjusted in the first embodiment. As shown in Fig. 9, the control unit 13 causes the third driving unit 10 to drive the stage 9 to move so that the sensor 11 is positioned on the optical axis of the laser beam 15d. Next, the control unit 13 monitors the energy of the laser beam 15d measured by the sensor 11 while moving the incident optical system 3, thereby adjusting the energy of the laser beam 15d incident on the sensor 11. The desired value.

Referring again to Fig. 8, in step S122, the control unit 13 causes the transfer optical system 7 to face the traveling direction 18 of the laser beam 15d or the direction opposite to the traveling direction 18 of the laser beam 15d in accordance with the movement of the incident optical system 3. 19 is moved to adjust the beam path of the portion of the laser beam 15d on the surface to be processed of the workpiece 14 that is higher than the processing threshold. At this time, the control unit 13 can determine the position of the transfer optical system 7 corresponding to the position of the incident optical system 3 by referring to the table 12a shown in FIG.

Further, in the above-described manner, the position of the transfer optical system 7 corresponding to the position of the incident optical system 3 is determined by the memory unit 12 in the memory table 12, but the state in which the table 12a is not stored in the memory unit 12 may be employed. kind. Specifically, it is also possible for the operator to operate the laser processing apparatus 1 such that the diameter of the portion of the laser beam 15d on the surface to be processed of the workpiece 14 that is higher than the processing threshold is desired. The position of the transfer optical system 7 is adjusted in a diameter manner. Further, the operator can adjust the position of the transfer optical system 7 so that the machining hole diameter actually formed in the workpiece 14 becomes a desired diameter while the laser processing apparatus 1 is being operated.

As described above, according to the first embodiment, even if the output of the laser oscillator 2 is lowered, it is possible to form a machined hole having a diameter of a required size in the workpiece 14. Therefore, according to the first embodiment, the usable period of the laser oscillator 2 can be extended, and the frequency of replacement of the laser oscillator 2 can be reduced. Therefore, according to the first embodiment, the cost of the laser processing can be reduced.

Embodiment 2.

Fig. 10 is a view showing the configuration of a laser processing apparatus according to a second embodiment. The laser processing apparatus 1A of the second embodiment includes a laser oscillator 2A capable of outputting a signal indicating a laser output in place of the laser oscillator 2 of the laser processing apparatus 1 of the first embodiment.

The control unit 13 can acquire the output of the laser oscillator 2A by the signal indicating the laser output received from the laser oscillator 2A. If the laser output of the laser oscillator 2A can be obtained, the position of the incident optical system 3 when the energy of the laser beam 15c becomes the desired energy can be determined. Therefore, the signal indicating the laser output and the laser beam 15c are obtained in advance. The relationship between the position of the incident optical system 3 when the energy is the desired energy, and the relationship between the position of the incident optical system 3 when the signal indicating the laser output and the energy of the laser beam 15c become the desired energy will be described. Table 12b is pre-memorized in the memory unit 12.

The control unit 13 determines the position of the incident optical system 3 with reference to the table 12b based on the signal indicating the laser output received from the laser oscillator 2A, and moves the incident optical system 3. Further, the control unit 13 determines the position of the transfer optical system 7 in accordance with the movement of the incident optical system 3 with reference to the table 12a, and causes the transfer optical system 7 to move.

As described above, according to the second embodiment, the operation of measuring the energy of the laser beam 15d by the sensor 11 can be saved. Therefore, according to the second embodiment, the efficiency of laser processing can be improved.

Further, in the first embodiment and the second embodiment, the relationship between the position of the incident optical system 3 and the position of the transfer optical system 7 is previously stored in the memory unit 12. However, the position of the transfer optical system 7 can also be adjusted each time laser processing is performed. That is, in the pre-preparation step before the laser processing, the position of the transfer optical system 7 is changed to perform laser processing, and the position of the transfer optical system 7 forming the desired processing aperture is determined.

When the divergence angle or intensity distribution of the laser beam 15a changes, the relationship between the position of the incident optical system 3 and the beam path on the mask 5 also changes. That is, the relationship between the position of the incident optical system 3 and the intensity distribution of the laser beam 15c passing through the opening 5a also changes. Therefore, in the first embodiment and the second embodiment, the table 12a of the memory unit 12 is stored in advance and The relationship of 12b has also changed and it may not be possible to continue to maintain the machined aperture to the desired diameter. However, if the position of the transfer optical system 7 is adjusted every time laser processing is performed, the processed aperture can be maintained at a desired diameter even if the divergence angle or intensity distribution of the laser beam 15a fluctuates.

Embodiment 3.

Fig. 11 is a view showing the configuration of a laser processing apparatus according to a third embodiment.

In the laser processing apparatus 1 of the first embodiment, the laser beam 15b is condensed at the condensing point 20, and is diverged to enter the mask 5.

On the other hand, in the laser processing apparatus 1B of the third embodiment, the laser beam 15b is incident on the mask 5 before being concentrated. Next, the laser beam 15c that has passed through the opening 5a is condensed at the condensing point 20.

In the third embodiment, if the energy of the laser beam 15a emitted from the laser oscillator 2 is lowered, the control unit 13 moves the incident optical system 3 in the opposite direction 17 of the traveling direction 16 of the laser beam 15a to reduce the lightning. The beam diameter of the beam 15b on the mask 5. Thereby, the control unit 13 can increase the ratio of the laser beam 15c to the entire laser beam 15b, and can maintain the energy of the laser beam 15c.

Fig. 12 is a graph showing the relationship between the position of the incident optical system, the position of the transfer optical system, and the processing aperture in the third embodiment. The graph shown in Fig. 12 is obtained by simulating the flow chart shown in Fig. 5.

In the chart shown in Figure 12, the horizontal axis represents the transfer light. The position of the system 7, the vertical axis represents the diameter of the portion of the laser beam 15d on the surface to be processed of the workpiece 14 that is higher than the processing threshold. Further, the "-" is used to indicate that the transfer optical system 7 is moved toward the traveling direction 18 side of the laser beam 15d, and "+" represents the reverse direction of the traveling direction of the laser beam 7 to the laser beam 15d. 19 side moves.

In Fig. 12, the position of the incident optical system 3 is shown as the reference position, the position of the incident optical system 3 is the position of +1 mm from the reference position, and the position of the incident optical system 3 is the position of +2 mm from the reference position. The case and the position of the incident optical system 3 are the positions of +3 mm from the reference position. Here, the "+" represents that the incident optical system 3 is moved toward the opposite side 17 of the traveling direction 16 of the laser beam 15b.

The line 60 is an approximate straight line of the sampling point when the position of the incident optical system 3 is the reference position. The line 61 is an approximate straight line of the sampling point when the position of the incident optical system 3 is +1 mm from the reference position. The line 62 is an approximate straight line of the sampling point when the position of the incident optical system 3 is +2 mm from the reference position. The line 63 is an approximate straight line of the sampling point when the position of the incident optical system 3 is +3 mm from the reference position.

Here, the desired processing pore size is set to 50 μm. At this time, the intersection point 64 of the diameter of the line 60, the line 61, the line 62, and the line 63 and the portion of the laser beam 15d on the surface to be processed of the workpiece 14 which is higher than the processing threshold is calculated. 65, intersection 66 and intersection 67. The values of the horizontal axis of the intersection point 64, the intersection point 65, the intersection point 66, and the intersection point 67 are incident when the position of the incident optical system 3 is the reference position of the transfer optical system 7. When the position of the optical system 3 is +1 mm from the reference position, the position of the incident optical system 3 is +2 mm from the reference position, and the position of the incident optical system 3 is at a position of +3 mm from the reference position. .

Specifically, when the position of the incident optical system 3 is the reference position, the position of the transfer optical system 7 becomes +260 μm from the reference position. Further, when the position of the incident optical system 3 is a position of +1 mm from the reference position, the position of the transfer optical system 7 is +200 μm from the reference position. Further, when the position of the incident optical system 3 is a position + 2 mm from the reference position, the position of the transfer optical system 7 becomes +75 μm from the reference position. Further, when the position of the incident optical system 3 is a position +3 mm from the reference position, the position of the transfer optical system 7 is +10 μm from the reference position.

Fig. 13 is a view showing a table memorized by the memory unit in the third embodiment. Table 12c shown in Fig. 13 is a diagram in which the position of the incident optical system 3 and the laser beam 15d are converted to a desired diameter when the diameter of the surface to be processed of the workpiece 14 is the desired diameter according to the graph of Fig. 12. The position of the optical system 7.

The control unit 13 moves the incident optical system 3 in the opposite direction 17 of the traveling direction 16 of the laser beam 15a to adjust the energy of the laser beam 15c passing through the opening 5a.

Further, the control unit 13 moves the transfer optical system 7 in the reverse direction 19 of the traveling direction 18 of the laser beam 15d in accordance with the movement of the incident optical system 3. That is, the control unit 13 takes the image of the opening 5a from The surface to be processed of the workpiece 14 is moved further toward the opposite side 19 of the traveling direction 18 of the laser beam 15d. Thereby, the control unit 13 blurs the image of the opening 5a on the surface to be processed of the workpiece 14. Thereby, the control unit 13 enlarges the beam diameter of the portion of the laser beam 15d on the surface to be processed of the workpiece 14 that is higher than the processing threshold. Thereby, the laser processing apparatus 1 increases the diameter of the machined hole, thereby forming a machined hole of a desired diameter.

As described above, according to the third embodiment, even if the output of the laser oscillator 2 is lowered, a machined hole having a desired diameter can be formed in the workpiece 14. Therefore, according to the third embodiment, the usable period of the laser oscillator 2 can be extended, and the frequency of replacement of the laser oscillator 2 can be reduced. Therefore, according to the third embodiment, the cost of laser processing can be reduced.

The configuration shown in the above-mentioned embodiments is an example of the present invention, and can be combined with other known techniques, and a part of the configuration can be omitted or changed without departing from the spirit of the invention.

S120, S122‧‧‧ steps

Claims (6)

A laser processing method includes the following steps: a first step of illuminating a laser beam emitted from a laser oscillator to an incident optical system of a mask toward a traveling direction of a laser beam or a laser beam Moving in the opposite direction of the traveling direction to adjust the energy of the laser beam passing through the opening of the mask; and in the second step, irradiating the laser beam after passing through the opening according to the movement of the incident optical system The transfer optical system to the workpiece moves in a direction opposite to the traveling direction of the laser beam or the traveling direction of the laser beam to adjust the diameter of the laser beam on the surface to be processed of the workpiece; the second step The beam diameter at a portion of the surface to be processed of the workpiece that is higher than the processing threshold of the laser beam is increased to a desired processing aperture. The laser processing method according to claim 1, wherein the second step is directed to the position of the incident optical system and the diameter of the laser beam on the surface of the workpiece to be processed. The position of the aforementioned transfer optical system is determined by a table of the relationship of the positions of the aforementioned transfer optical systems at the time of diameter. A laser processing method includes the following steps: a first step of illuminating a laser beam emitted from a laser oscillator to an incident optical system of a mask toward a traveling direction of a laser beam or a laser beam Moving in the opposite direction of the traveling direction to adjust the energy of the laser beam passing through the opening of the mask; and In the second step, according to the movement of the incident optical system, the laser beam that has passed through the opening is irradiated to the transfer optical system of the workpiece, toward the traveling direction of the laser beam or the traveling direction of the laser beam. Moving in the opposite direction to adjust the diameter of the laser beam on the surface to be processed of the workpiece; the first step is described by referring to the signal indicating the laser output received from the laser oscillator and passing through the opening The position of the incident optical system is determined by a table showing the relationship between the position of the incident optical system when the energy of the laser beam becomes the target energy. A laser processing apparatus includes: an incident optical system that irradiates a laser beam emitted from a laser oscillator to a mask; and a transfer optical system that irradiates a laser beam that passes through an opening of the mask And the control unit performs control for moving the incident optical system in a direction opposite to a traveling direction of the laser beam or a traveling direction of the laser beam to adjust a laser beam that passes through the opening Energy, and according to the movement of the aforementioned incident optical system, the aforementioned transfer optical system is moved in the opposite direction of the traveling direction of the laser beam or the traveling direction of the laser beam to adjust the laser beam on the processed surface of the workpiece The diameter of the beam is increased to a desired machining aperture at a portion of the surface to be processed of the workpiece that is higher than the processing threshold of the laser beam. The laser processing apparatus according to claim 4, further comprising a memory unit that memorizes the position of the incident optical system and the diameter of the laser beam on the surface to be processed of the workpiece to be the target diameter. A table showing the relationship between the positions of the transfer optical systems; the control unit determines the position of the transfer optical system by referring to the table. A laser processing apparatus includes: an incident optical system that irradiates a laser beam emitted from a laser oscillator to a mask; and a transfer optical system that irradiates a laser beam that passes through an opening of the mask And the control unit performs control for moving the incident optical system in a direction opposite to a traveling direction of the laser beam or a traveling direction of the laser beam to adjust a laser beam that passes through the opening Energy, and according to the movement of the aforementioned incident optical system, the aforementioned transfer optical system is moved in the opposite direction of the traveling direction of the laser beam or the traveling direction of the laser beam to adjust the laser beam on the processed surface of the workpiece The diameter is further provided with a memory portion that describes the position of the incident optical system when the signal indicating the laser output received from the laser oscillator and the energy of the laser beam passing through the opening become the target energy. A table of relationships; the control unit determines the position of the incident optical system by referring to the aforementioned table.